The instruments will support a large number of diverse NIH-funded studies. Structural studies of hormones (relaxin), ferritin, T-cell antigens and receptors, tumor antigens, active sites of intracellular proteases, the structure of fish IgM, and structural changes in macromolecular components of connective tissues. In every case the studies are limited by the amount of sample available. The addition of a gas phase sequencer, high sensitivity amino acid analyzer, and peptide synthesizer will allow significant advances in any of these areas of research. In addition to greater sensitivity these instruments are faster than the older instruments and will therefore allow us to accommodate the experimental needs of 8-10 occasional users of the protein chemistry facility.